Risk Factors for Hyponatremia and Perioperative Complications With Malignant Intracranial Tumor Resection in Adults: An Analysis of the Nationwide Inpatient Sample from 2012 to 2015.

Background: The present study aims to study the incidence and risk factors for developing hyponatremia and associated perioperative outcomes in adult patients admitted for malignant brain tumor resection.

Methods: The 2012-2015 Nationwide Inpatient Sample was queried for all patients undergoing surgical resection of malignant brain tumors. These patients were then grouped by the presence of concurrent diagnosis of hyponatremia, and compared with respect to various clinical features, perioperative and postoperative complications, all-cause mortality, discharge disposition, length of stay, and hospitalization costs. Propensity score matching was utilized to control for appropriate baseline confounders and the influence of other endpoint variables.

Results: The search criteria identified 12,480 adult patients admitted for malignant brain tumor resection, of whom 1162 (9.3%) developed hyponatremia in the perioperative period. Patients with obstructive hydrocephalus (risk ratio [RR] = 1.23, P < 0.001), diabetes (RR = 1.14, P = 0.014), hypertension (RR = 1.15, P < 0.001), and depression (RR = 1.24, P < 0.002) were more likely to develop hyponatremia. Tumor location was not associated with risk of developing hyponatremia. Patients with hyponatremia were more likely to require ventriculostomy (RR = 1.23, P < 0.001), ventriculoperitoneal shunt (RR = 1.34, P < 0.001), and lumbar puncture (RR = 1.25, P < 0.001), and were also more likely to be discharged to short-term hospital (RR = 1.25, P < 0.001) or rehabilitation (RR = 1.21, P < 0.001), as well as have longer hospital stay (P < 0.001) and increased hospital charges (P < 0.001).

Conclusions: Patients with obstructive hydrocephalus, diabetes, hypertension, and depression were more likely to develop perioperative hyponatremia. Hyponatremia was associated with increased morbidity following malignant brain tumor resection.